Re: (ET) When did they start making car batteries out of gold?? :-)

["Barry" <Barry fredericktown com>]

I installed 12 100 ah CALB cells from Don in my EGT-200 on about July 20
2013 along with three used 12v AGM batteries for my accessories, a custom 
15
amp charger from "Quick Charge Corp" that cuts off at 43.2 volts and a 
36-12
volt converter to charge the 12 volt batteries. I should have bought a
smaller charger and saved money. The mower is working better than ever. It
is quite a bit faster. The voltage only dips slightly from a light load to 
a
very heavy load. I mow about 1.5 hours with only a very slight drop on the
fuel gauge. I should be able to mow for 2 hours plus.
I checked the cells today after a full charge with the charger disconnected
with a $4.00 meter from Harbor Freight.
The voltages were:
9 at 3.29
3 at 3.31
I performed NO balancing or pre installation charging or discharging of any
sort on the cells. I installed them as they came from Don.
The 12 cells only take up about 1/2 the area under the seat which leaves
room for one of the 12v AGM batteries. The other two 12 volt AGM batteries
are in the front with the charger. You can see that the lightness of the
lithium cells is NOT a problem as many people have mentioned. You can just
add more weight as required. You can empty the acid out of some of your 6
volt batteries and leave them in the tractor. If you only use your tractor
for mowing you do not have to add any weight.

I am not using a BMS. With the charger limited to 43.2 volts I feel that 
the
cells will remain in balance. I expect these cells to last 15+ years. The
lead acid batteries lasted 6 years.
There may or may not be a cost savings with the lithium cells but, I will
never have to water these cells, there will be no more corrosion and 
rusting
of the battery boxes, no more loose or burnt up cable, no more lifting of 
62
lb flooded lead acid batteries and with the new charger I will not have to
think about how long to set the charger for.

I temporally installed 12, 40 ah CALB cells and was able to mower for 45
minutes. Those 40 ah cells are now in my golf cart which goes 9 miles on a
charge.

You can see pictures are:
http://electricfordranger.com/BarrysEGT200.aspx
I engineered and helped with the lithium upgrade to the Ranger. It does not
have a BMS. The 104, 100 ah cells also came from Don.


Barry Elkin
barry fredericktown com

www.electricgvan.com
www.fredericktown.com/chriscraft/restored
www.electriccorvair.com


-----Original Message-----
From: David Roden (Akron OH USA) [mailto:etpost drmm net] 
Sent: Thursday, August 15, 2013 9:46 PM
To: elec-trak cosmos phy tufts edu
Subject: Re: (ET) When did they start making car batteries out of gold?? 
:-)

On 15 Aug 2013 at 18:44, Theoldcars aol com wrote:

> Its a good thing battery chemistry has improved because now there are 
> better options.

Completely passing over the political comments in Don's post, I must say
that while batteries HAVE indeed improved, and while I think lithium
(particularly LiFePO4) batteries are crucial to building successful road
EVs, lead batteries are still the better option for most ETs.  

For one thing, in most cases, we WANT the mass lead provides.  That's
definitely not the case in a road EV.

Lead is also far more forgiving of careless charging.  Flooded lead
especially will shrug off all but severe overcharging.  Overdischarging 
will
shorten its life, but it's not catastrophic.  Compare that with the babying
a lithium battery needs.  

When you change to a lithium battery, don't forget to count the cost of the
cell-level BMS (battery management system) it requires.  Hobbyist users
sometimes leave the BMS out.  In some cases this is because they want to
save money.  Others just don't know or think it's necessary.  Some think
they can do manually what a BMS does.  A few actually think a BMS is
counterproductive.  

Not that I want to be alarmist, and I know things can also go wrong with
lead, but lithium systems DO have to be managed. Lithium batteries have
shown not only a propensity to die when improperly charged, but to do so in
a violent manner at times.  The good news is that lithium stores a lot of
energy and can produce a lot of power.  That's also the bad news.

You have to watch them all the time - or your BMS does.  I really don't
think you can be your lithium battery's manual BMS unless you don't have a
life.  

Besides its forgiving nature, lead remains a very low use-cost battery,
especially for the generally relaxed life it lives in an ET (compared to a
road EV).  

The roughest part of a lead battery's life in an ET is being charged by 
that
blunderbuss of a GE charger.  Despite that, lots of ETers get 10 year
battery life.  Replace the GE charger with something gentler and smarter,
and I'd guess you'd see a good 15 year battery life.  In fact, I've been
using the same East Penn gel batteries in my ET now since 1997 or 1998, and
my chargers aren't even that smart (though smarter than the GE).  

Meanwhile, as I understand it, lithium batteries have a calendar life apart
from their cycle life.  

There may come a time when large lithium batteries are produced in
quantities as massive as golf car batteries are now.  Maybe then they'll be
as much of a commodity as lead batteries are now.  When that happens, we
might find ourselves using lithium in places where lead actually is the
better choice, just because lithium is so cheap.  But not now.



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